STARLIGHT ON THE ACADIA ALL AMERICAN ROAD

Maine’s spectacular rocky coast is home to Acadia National Park and some of the last star-filled skies in the country. Here the Milky Way shines bright in the largest expanse of naturally dark sky east of the Mississippi. As the rapid loss of dark skies to light pollution receives national recognition, Maine is increasingly referred to as a place “that still has stars.”

To protect some of the last natural skies in the country, in 2001 the National Park Service took the step of formally recognizing the night sky as a natural resource:

“The service will preserve, to the greatest extent possible, the natural lightscapes of parks, which are natural resources and values that exist in the absence of human caused lighting.”

Its General Management Policy instructs the Service to seek the cooperation of “neighbors and local government agencies to prevent and minimize the intrusion of artificial light into the night scene of the ecosystems of parks.”

"This Outstanding Aspect of the Community”

The Acadia All American Road begins at the bridge onto Mount Desert Island. As the Byway follows the coast of the rugged island, it passes through the town of Bar Harbor and into the mountainous heart to Acadia National Park.

According to Bar Harbor’s 2007 Comprehensive Plan, its residents “highly value the community’s dark skies” and want the town to “reduce light pollution to mitigate the risk of losing this outstanding aspect of the community.” Bar Harbor’s plan echoes the National Park’s commitment to protecting the night sky. It directs the town to implement a “dark skies management plan and ordinance.”

The unshielded street and business lights used extensively along the Byway are a major source of the stray light threatening to obscure Acadia’s night sky. Since 1991, Maine law has required the use of full-cutoff roadway lighting when state funds are involved. Maine’s Act to Improve Outdoor Lighting assigns oversight responsibility to the Maine Department of Transportation, the same department responsible for the Acadia All American Road.

None of the lights on the Acadia All American Road are shielded. They are installed by the local power company, which does not offer full-cutoff shielding. Bar Harbor’s unshielded street lights (left) are concentrated on its downtown business district, where the highest levels of light pollution (shown in red on the right) were first measured by College of the Atlantic Students in 2007.

Reflecting the federal, state and local concerns of its governing committee, the Acadia All American Road chose to add the night sky to its list of natural resources, becoming the first Scenic Byway to do so.

The committee has commissioned an inventory of the conditions along the Byway. These five initial Nightscape Surveys document the best and worst night-sky qualities along the Byway. Two additional surveys commissioned by Friends of Acadia are presented as well. The first is on the proposed Byway extension, at the future location of the Acadia Gateway Center; the second, on top of Schoodic Point in Acadia National Park, is on the Schoodic Scenic Byway.

The inventory establishes the brightest and the most concentrated sources of light pollution, called “light domes,” on the roadway. This light dome brightness inventory is intended to help manage the conditions on the Byway by identifying the impact from new sources, and changes such as the replacement of unshielded street and business lights with shielded ones.